Alright gang, I'm at the end of the game at the Black Gate. My problem is the AI on my team mates sucks beyond belief, the enemy specifically targets them, and I keep getting swamped by the Champions I'm supposed to kill several of. Any thoughts on how best to beat this?

If you stand close to your team mates, you'll see them glow up. This means they're healing. So just fight near the person that has low health. And especially keep an eye out for legolas, he can die very fast. Unless you're playing as Legolas of course, in which case you will die very fast